Railway-traffic-controlling apparatus



G. w. BAUGHMAN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed March 26. 1927 March 20, 1928..

6 M185; idi F 1 Fig. 2.

INVENTORI G Baa/" 11011",

Patented Mar. 20, 1928.

UNITED STATES 1 1,662,950 PATENT OFFICE.

GEORGE w. BAUGHMAN, or nnenwoonisonouerr, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY,

PORATION OF PENNSYLVANIA.

0F 'SWISSVALE, PENNSYLVANIA, A COR- R'AILWAY-TRAFFIOCONTROLLING APPARATUS.

Application filed March 26, 1927. Serial No. 178,617.

I will describe one form of railway traflic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 1s a diagrammatic view showing one form of railway trafiic controlling apparatus embodying my invention. Fig. 2 is a view, partially diagrammatic, showing in front elevation the train carried receiver R located over the auxiliary loo circuit J of Fig. 1.

Similar re erence characters refer to similar parts in both views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a stretch of railway track over which traili'c normally moves in the direction indi cated by the arrow. These track rails are divided, by means of insulated joints 2, into a plurality of successive track sections, only one of which, A B, is shown in the drawing. Means are provided for supplying each'such track section with train controlling current, and for this purpose section A-B is provided with two impedances 1 and 5 connected across the rails adjacent the entrance end and the exit end, respectively, of the section. The secondary 6 of a loop transformer L is connected with the midpoints of impedances 4 and 5 and alternating current is continuously supplied to the pr1mary 7 of transformer L from a suitable source of energy, such as an alternator M, over line wires 3 and 3. It follows that alternating train controlling current is continuously supplied to the rails of section A--"B in parallel, and this current I shall hereinafter call the loop current. Referring now also to Fig. 2, a train indicated diagrammatically at V is provided with a train carried receiver R comprising a .mag netizable core 9. The core 9 is, provided with a pair of downwardly projecting legs 10 and 11 locatedfon opposite sides of rail 1, and with another pair of downwardly projecting legs 12 and 13 located on opposite sides of rail 1. The 1egs10,:11, 12 and 13 are provided with windings 10*, 11*, 12 and 13*, respectively. It will be plain from an.

inspection of Fig. 2 that loop current flowing in the same direction in the rails 1 and 1 at an instant creates magnetic fluxes in the paths indicated in Fig. 2 by the dot and dash lines 25 and 26. It will'also be plain that the direction of these fluxes is the same at an instant as shown by the arrows. The windings 10, 11 12 and 18 are connected in series in such manner that thevoltages induced therein by the fluxes which traverse the paths 25 and 26 are additive. In other words, the voltages induced inthe receiver windings by loop current in the track rails are addltlve. The I'GCGIVGI windings are connected through a suitable amplifier 14 with a winding of a relay K which may control train carried governing means in-any suitable manner.

Under some conditions of operation it may be desirable to supply the relay Kwith a larger amount of energy than is normally supplied to this relay due to the loop current which flows through the-track rails, and this is usually done by installing auxiliary loop c rcuits at certain points in the trackway.

"One form of apparatus involving these auxdesignated J, comprises two conductors 15 l and 16 disposed in the trackway adj acent the 1 track rails 1 and 1 respectively. A third conductor 17, parallel to theconductors 15 and 16 is located substantially mid-way between the rails 1 and 1. The left-hand ends of the conductors 15, 16 and 17 are con-; nected together at a common point (Z. Gurrent is at times supplied to the conductors of the circuitJ from a transformer T comprising two secondaries 18' and 19 and a primary 20 which is constantly connected with line'w'ires' 3 and 3. Terminals of like in stantaneous relative polarity of the secondaries 18 and 19 are connected together and with the right-hand endof the'conductor 17. vThe remaining terminal of secondary 19 is connected with the right-hand and of conductor 15, and the remaining terminal of secondary 18 connected with the free end of conductor 16. It follows thatthetransin conductors and 16, and in the opposite former T supplies alternating current to the auxiliary c1rcuit J in such manner that current flows in the same direction at an instant direction at the same instant in conductor 17.

When the receiver R is located over the auxiliary circuit J, if the instantaneous di-' rection of the loop current in the rails is such that the direction of the alternating fluxes created thereby is as indicated by the arrows on the lines 25 and 26, the fluxes created by the currents in the conductors 15, 16 and 17 will follow the paths shown in dotted lines at 20, 21 and 22, respectively in the direction indicated by the arrows on such lines. It will be plain therefore that the fluxes created in the receiver core by the currents in the conductors of: the auxiliary loop circuit J traverse the receiver windings in the same direction as the fluxes created 1n the receiver by loop (current in the track rails. It follows that the magnitude of the voltages induced in the receiver windings is materially increased and that the energy supplied to relay K is correspondingly increased when the receiver isover the auxiliary loop circuit.

My invention is of particular advantage in connection with the usual track circuit including the usual track relay connected across the rails. The tendency of current in conductor 15 to induce a voltage in such a track circuit is neutralized by an equal and opposite inductive effect from the current in conductor 16. Since conductor 17 is located midway between the rails, the voltage induced in rails 1 and 1 by current in conduc tor 17 are equal and opposite. It follews that with auxiliary loop circuits constructed in accordance with my invention no electromotive force whatever is induced in the track circuit by the currents in the auxiliary circuit.

Although I have herein shown and de scribed only one form of railway traflic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims withoutdeparting from the spirit and scope of my invention. i

Having thus described my invention what I claim is:

1. Railway traflic controlling apparatus comprising three parallel conductors located in the trackway and connected together at one end, and two sources of alternatiing current haviing a common terminal connected with the free end of one conductor, the remaining terminals of said sources being connected with the free ends of the remaining conductors respectively. 7

2. In combination with a train carried receiver comprising a magnetizable core having two pairs of legs projecting downwardly on opposite sides of the two rails respectively, means located in the trackway for creating alternating fluxes through such pairs of legs in the same direction, and means also located in the trackway for creating an alternating flux' in the core which passes through ony the two inner legs of the core in the same direction as the first mentioned fluxes.

3. Railway traffic controlling apparatus comprising two parallel conductors located adjacent the two track rails respectively and connected together at one end in a common point, and two sources of alternating current having their terminals of like instantaneous polarity connected with such common point and having their remaining terminals connected with the free eds of the conductors respectively.

at. Railway traific controlling apparatus comprising twoparallel. conductors located 7 ends of said two conductors respectively.

5. In combination with a stretch of railway track, means for supplying the rails of the stretch with alternating loop' currents which flow inthe same direction in the track rails at an instant, a train carried receiver comprising a plurality of windlngs connected in series in such manner that the voltages. induced therein by loop currents in the track rails are additive, two conductors located in the trackway parallel with the track rails respectively, a third conductor parallel with and substantially midway between the rails and means for supplying the three conductors with alternating currents which induce in the receiver windings voltages which are in the same direction as the voltages induced in such windings by loop current in the rails.

6. In combination with. a train carried receiver comprising windings inductively related to the track rails, three parallel conductors located in the trackway, and means for supplying to the conductors alternating currents which flow in one direction in two of the conductors and in the opposite direction in the remaining conductor, said two conductors being located adjacent the two track rails respectively and the third conductor being. located midway between the rails whereby such currents induce voltages in said windings but not in the track'rails. In testimony whereof I airix mysignature.

GEORGE W. BAUGHMAN. 

